A device which is suitable for carrying out these steps is frequently also designed for the purpose of placing unused and used vessel arrangements in storage devices (stackers) vertically, removing the same from stackers, and transporting the vessel arrangements between the stackers and individual work spaces. In the process, the vessel arrangements are moved horizontally, for example via transport sleds, and vertically, for example by means of lifters.
The technical features which such a device must have proceed from the technical steps which must be carried out, and which can vary in their sequence and the process parameters thereof.
A device in the class is known from DE 2008 061 714 A1. A device disclosed therein, designed for the use thereof together with multiple vessels (“sample vessels” in the document), has the following features:
a surface for the vessels;
a temperature-controllable device with receptacles for the vessels;
a vessel carrier plate (“sample vessel holder” in the document) with annular magnets, wherein the vessels can be received in the interiors thereof;
a device for the transport of vessel carrier plates from the surface to the temperature-controllable device;
a device for the transfer of liquid from the vessels into other vessels, or into a disposal container; and
a control device for controlling the transport device, the device which transfers liquid, and for the controlling the temperature of the temperature-controllable device.
DE 10 20008 061 714 A1, named above, also states that in the prior art a holder has rod-shaped magnets rather than annular magnets, which form a magnetic field working on one side.
From the few details on the device given in DE 10 2008 061 714 A1, it can be clearly derived that a vessel carrier plate equipped with vessels can be connected to the temperature-controllable device to heat the vessels, in such a manner that the vessels can be received by the receptacle of the temperature-controllable device, thereby bringing the vessel carrier plate, and therefore the magnets integrated into the same, into direct contact with the temperature-controllable device, and warming the same as well when the vessels are warmed.
This has the disadvantage that, over the total duration when the vessels are held in the vessel carrier plate—that is, also during a heating of the sample liquid in the vessels, for example to temperatures up to 50° C. for lysing or eluting, or to temperatures up to 40° C. for drying the magnetic particles in the sample vessel—each of the vessels is exposed to a magnetic field and the magnets are warmed at the same time. In this process, the temperature on the heating plate is temporarily more than 40° C. higher than the temperature in the interior of the vessels, due to the dynamically controlled heating profile.
It is not known whether a magnetic field has an effect which influences the lysing process. However, it is known that a plurality of magnetic materials change their magnetic properties when heated. For this reason, according to DE 10 2008 061 714 A1, named above, only selected magnetic materials having a high Curie temperature can be used, which have properties which do not change at these temperatures. To avoid small de-magnetizations, the maximum applied temperature is preferably set a whole step below the Curie temperature. Additional limiting parameters are set by the limited constructed size of the magnets in the heating magnet module, and the coating needed for each magnet, which must allow a thorough cleaning and decontamination, which creates a limitation due to costs in practice in the industry.
A substantial disadvantage of a vessel carrier plate (called a sample vessel holder) according to DE 10 2008 061 714 A1, named above, is the magnetic effect on the vessels, and therefore on the magnetic particles, during the drying of the magnetic particles as well. As a result of the effect of the magnetic field, the magnetic particles are deposited on the vessel walls, stuck to each other, and the magnetic particles must therefore be dried over a longer period of time than if they were loose in the vessel wall. In addition, the action of the magnetic field, together with the evaporation of the liquid, leads to a too-strong agglomeration of the magnetic particles, such that they are much more difficult to homogenize in solution upon the subsequent addition of an aqueous solution.
In actual practice, devices are also known wherein the heating of vessel arrangements, and the insertion thereof into magnetic fields, takes place on work spaces which are separated from each other. In this case, the particularly increased space requirements for two work spaces which are separated spatially is a disadvantage.